Where is your 12v+ on your tach hooked up to?

[TIMSPEED]

I have mine hooked up to the IGN spot on the fusebox...but when I turn my truck off, the tach needle just wraps around, in a counterclockwise rotation. So, maybe there's a better spot for it. Where's yallz hooked up to? I was thinking of hooking it up to that spot on the outside of the firewall, that little box that has constant 12v+.

[SanitysBane]

i found a keyed power wire that didn't have a fuse in it, and stuck a spade into and used that for my tach, tq lock up, and radio.

[NeCrOmAnCeR]

If you connect it to a constant hot, it will act as a parasitic drain and will constantly be turned on. You might try connecting a capacitor (couple thousand uF, 25 Volt) between ground and the tach hot lead to kill power to it slowly (a blocking diode will be required too) This would keep it powered up for a few seconds after you kill the ignition and hopefully keep it from going crazy.

[Prerunner1982]

i just found a keyed open spot on the fuse block and stuck a spade in it. i had it hooked to constant power and i think it was either that or my alt or both that were draining my battery.